FACT: Of course if you’re pushing yourself on that treadmill or elliptical day in and day out, you will drop weight and you will drop it fast. Cardio alone, however, burns away both fat and muscle, which of course you don’t want. Make sure the weight you lose is the right kind of weight. You need those muscles!
FACT: All body movements burn calories, not just the ones that keep your heart pumping for over an hour. To burn them more efficiently, in fact you should introduce high-intensity interval training to routine which can elevate your metabolism so that you could still be burning up to 38 hours after your workout. Even 10 minutes at a high intensity is beneficial. And a suggests that short, infrequent bouts of slow running can do your heart good.
FACT: Although it may seem like you're working your legs and glutes, you aren't getting any muscle building benefits by running or biking. Building up these large muscles in your body help boost your metabolism so you need to do strength moves along with your cardio. And as an added bonus, strength will make you a better runner and cyclist.